Liquid chemical injector for use in wells



Feb. 13, 1962 w. P. oRR

LIQUID CHEMICAL INJEC'IOR FOR USE IN WELLS INVENTOR.

WILLIS. P. ORR,

#ML .Im

Filed Dec. 16, 195'? L se HTFR!! FIG. I.

ATTORNEY.

United States Patent C) 3,020,961 LIQUID CHEMICAL INJECTOR FOR USE INWELLS Willis P. Orr, Tyler, Tex., assignor, by mesne assignments,

to Jersey Production Research Cmpany,-Tulsa, Okla.,

a corporation of Delaware Filed Dec. 16, 1957, Ser. No. 702,909 8Claims. (Cl. 166-165) This invention relates to well treating. Moreparticularly, this invention relates to a novel device .for chemicallytreating the well tubing with a corrosion inhibitor,

Briefly described, the invention includes a tubular container providedwith a chamber for holding the fluid for treating the tubing. At leastone outlet orice is provided in the container adapted to be placed incommunication with the chamber. Means are provided for normallypreventing the ow of the fluid from the chamber to the outlet orice.Pressure responsive means,

ldisposed Within the chamber, is used for opening-the `normally closedmeans for preventing flow to the orifice from the chamber. When thepressure responsive means is actuated, the chemical is ejected from thechamber and through the orice to be sprayed upon the inside of the welltubing.

Another aspect of this invention is the provision of a wiper memberwhich is normally in an extended position against the well tubing. Whenpressure such as the well pressure is applied against the wiper member,it collapses against the side of the container, thus permitting thecontainer to be dropped or lowered into the tubing. The inside of thecollapsible wiper member is in pressure communication with a chamber inthe container. Means are provided for admitting the well pressure intothe chamber after the device has been lowered into the tubing to extendthe wiper against the inside of the tubing. Hence, after the containerhas been lowered into the well and the chemical or well treating uidsejected against the inside of the tubing, the wiper is extended againstthe tubing. When the container is flowed to the surface, the wipermember thus performs a wiping and distributing action on the treatinguids or chemicals.

The invention and its advantages may be further understood by referenceto the following drawings and detailed description, in which:

FIG. 1 is an elevational view partially in section showing the containerfalling through the well tubing with the wiper member collapsed againstthe side of .the container;

FIG. 2 is an elevational view partly in section showing the parts of thecontainer after the treating chemicals ,have been sprayed against theinside of the well tubing and the wiper member extended against thesides of the tubing;

FIG. 3 is a view showing the necessary well head equipment for insertingthe device of the present invention into the Well tubing;

FIG. 4 is a sectional view showing a modiiied form of means forpreventing the flow of chemicals from the chamber until a predeterminedpressure within the well is reached;

FIG.Y 5 is still another view showing a still further means forpreventing the ejectment of the chemicals or well treating fluids fromthe chamber until the predetermined well pressure is obtained; and

FIG. 6 is a view in vertical section showing the wiper in detail.

Referring to the figures, and particularly to FIGS. 1 and 3, a bore 10is shown provided with a casing 12. A

2. tubing or pipe string 14 extends into the bore 10 and provides anannulus 16 between the casing 12 and the tubing.

Located at the surface or wellhead is the usual surface equipment, suchas a Christmas tree 18 and a lubri- `cator 20 provided with valvemembers 22 and 24.

The new device includes an elongated tubular container 26 which isadapted to be lowered or dropped through the tubing 14. The container 26is provided with an elongated chamber which is divided into two sectionswith one section of smaller cross-sectional area than the other section.The smaller cylinder 28 is used to initially contain the well treatingfluids, such as corrosion inhibitors. The larger chamber 30 contains adiierential pressure responsive means, to be subse. quently described.

At least one spray orifice 32 is provided in the upper portion of thecontainer 26. Orifices 32 are adapted to be placed in communication withthe smaller crosssectional portion 28 of the container chamber. Meansare provided for normally preventing the ejection of the chemicalthrough the orifice, such as a ball valve 34, spring biased by a spring36 against a valve seat 38.

The differential pressure responsive means may include a rst piston 40and a second piston 42, longitudinally separated from the tirst piston.Pistons 40 and 42 are interconnected by an elongated piston shaft 44.The cross-sectional area of piston 40 is substantially the same as thesmaller cross-sectional portion 28 of the chamber. The cross-sectionalarea of the larger piston 42 is substantially the same as the largercross-sectional portion 30 of the chamber. Piston 40 reciprocates withinportion 28 and piston 42 reciprocates within chamber portion 30. Theupward movements of pistons 40 and 42 are limited by shoulders 46 and48, respectively, formed in the container. O-ring seals 41 and 43 onpiston 40 and O-ring seals 45 and 47 on piston 42 provide fluid tightseals to prevent iluid from getting between pistons 40 and 42.

Extending upwardly from the bottom 50 of the charnber is a cylindricalpiston support 52. Cylindrical piston support 52 limits the downwardmovement of pistons 40 and 42. Piston support 52 being of smallercrosssectional area than the lower portion 30 of the chamber, providesspace 54 in communication with ports 5 6. Hence, the well pressure isexerted against the free end of piston 42 through ports 56 and space 54.

Also mounted on the outside of the container 26 is a collapsible wipermember S8. The collapsible Wiper member is normally held in its extendedposition. The wiper member is tubular in shape, and in construction,consists of individual bow springs 62 vulcanized to rubber 64. Therubber 64 is connected to slidable rings Y.66 and 67, which slide withina circular groove 68 formed on the outside of the container 26. Rings 66and 67 slide toward one another as the wiper member is extended toengagement with the tubing and away from one another as the wiper memberis collapsed. O-ring 69 1n slidable ring 66 and O-ring 71 in slidablering 67 form a fluid tight seal.

The wiper member straddles pressure equalizing ports 70, whichinterconnect the inside of the wiper member and the largercross-sectional portion 30 of the chamber. Pressure equalizing ports 70are positioned longitudinally with respect to the larger cross-sectionalportion 30 of the chamber to permit the free end of piston 42 to bemoved past the ports (see FIG. 2).

A shock spring 72 is provided about a lower portion 74 of the container26 to cushion the impact of the container if it is allowed to fallagainst a mechanical tubing stop 76 placed within the tubing 14.

In operation, the smaller cross-sectional area of the chamber 28 isfilled with the well treating uid, such as a corrosion inhibitorchemical. The weight of the fluid rests on the top free end portion ofpiston 4), thus moving piston 42 on the piston rest 52, as shown in FIG.l. The container is then placed in the lubricator 20 at the surface ofthe well. The rubber wiper 58 will flatten to the outside wall of thecontainer when the lubricator is brought to wellhead pressure due to thefact that the chamber within the container will be at atmosphericpressure. With the wiper collapsed, valve 24 is opened and the devicewill fall freely in the tubing until such time as piston 42 moves upwardpast the equalizing orifices 70 under the rubber element, thus againequalizing the pressure on each side of the rubber and allowing it toreturn to its normal expanded position and occupy the full inside areaof the tubing 14.

The area of piston 42 is larger than that of piston 40. Then, assumingthat the wellhead pressure is, say 2000 p.s.i., the pressure inside thesmaller cylinder will be 2000 times the ratio of the area of piston 42to the area of piston 40 and the differential pressure attempting tounseat the check valve 34 will be this liquid pressure minus 2000 p.s.i.If we should want the chemical ejection to start at a hole pressure of4000 p.s.i., then the pressure inside the smaller cylinder would be 4000times the ratio of the piston areas and the differential pressuretending to unseat the check valve 34 would be this pressure minus 4000p.s.i.; therefore, we would use a check valve that would unseat at thispredetermined differential pressure. When the check valve 34 moves offits seat, the pistons will move upward due to the difference in theirareas and the liquid will be displaced out of the cylinder. As piston 42moves past the equalizing orifices 70, the wiper member 58 will returnto its normal position as the pressure is equalized across it, and whenthe well is fiowed the tool will return to the surface where it can becaught in the lubricator and removed for refilling.

The flowing out of the tool is accomplished by flowing fluid down thewell through the annulus 16 between the tubing 14 and casing 12, andthen from the bottom of the well up the inside of the tubing 14 to carrythe container 26 up to the surface.

The container 26 may be dropped to the lower portion of the tubing andagainst the mechanical stop 76, where the corrosion inhibitor is ejectedthrough orifices 32 against the inside of the lower part of the tubing.However, it is possible by using my new tool to place the corrosioninhibitor at any desired location within the tubing and even to spray aprotective covering on the inside of the tubing as the container islowered through the tubing. For this purpose the container 26 may belowered into the tubing at any desired rate by a wire line, for example.The check valve 34 is adjusted so that chemical injection will start atsome predetermined point. The rate of movement of piston 40 ispredetermined by the size of the holes 32 in the head of the containerso that the chemical will be sprayed on the tubing walls as the toolfalls. At some desired point in the tubing above the tubing stop, piston42 will pass the equalizing orifice 70, thus allowing expansion of thewiper 58, thereby stopping the tool at this point. By owing the well thetool is returned to the lubricator.

An objective of preventing corrosion on tubing is to provide a uniformfilm of inhibitor on the walls of the tubing. The wiping and smearingaction of the wiper 58 as the tool ows to the surface aids indistributing the protective chemical over all the inside surface of thetubing. This wiping action will also remove deposited condensed acidsalts on the tubing walls and collar recessions in the upper portion ofthe tubing string.

In place of the check valve shown in FIG. 1, a rupture disc 80, such asshown in FIG. 4, may be used as a means for preventing the ejection ofthe chemical until the predetermined well pressure is reached. Also,instead of a check valve, as shown in FIG. l, or a rupture disc, asshown in FIG. 4, a shear pin may be mounted in the chamber' in aposition to prevent the movement of piston 42 until the predeterminedwell pressure is reached.

It is to be understood that the schematic drawings shown are merelyillustrative of my new invention, and that various. modifications andchanges may be made without departing from the scope of the appendedclaims.

I claim:

l. A device for depositing a chemical in a well comprising: a normallyvertical elongated tubular container provided with an elongated chamberdefined by the inside of the tubular container and having one elongatedportion of larger cross-section than `another elongated portion, and anoutlet orifice in iiuid communication with the smaller cross-sectionalportion; a chemical contained within the smaller cross-sectionalportion; means normally preventing the ejection of the chemical throughthe orifice and responsive to a predetermined well pressure to permitthe ejection of the chemical through the orifice; a smaller pistonhaving a cross-sectional area substantially the same as the smallercross-sectional portion of the chamber and a larger piston having across-sectional area substantially the same as the largercross-sectional portion of the chamber; a piston shaft interconnectingsaid pistons and having a length sufficiently long to restrain movementof the smaller piston to within the smaller cross-sectional portionregardless of the position of the larger piston; said pistons beingdisposed within the chamber so that the chemical in the smallercross-section of the `chamber normaly rests against the free end of thesmaller piston; and means permitting the well pressure to be exertedagainst the free end of the larger piston causing at a predeterminedwell presure the overcoming of the means normally preventing theejection of the chemical through the orifice.

2. A device in accordance with claim 1 wherein the means normallypreventing the ejection of the chemical through the orifice is a shearpin mounted in the chamber and against the shaft side of the largerpiston so as to hold the larger piston against motion until thepredetermined pressure is applied against the larger piston.

3. A device in accordance with claim l wherein the means normallypreventing the ejection of the chemical through the orifice is a valvemember in the fluid flow path from the smaller cross-sectional portionto the orifice.

4. A device in accordance with claim l wherein the means normallypreventing the ejection of the chemical through the orifice is a rupturedisc in the fluid liow path from the smaller cross-sectional portion tothe orifice.

5. In a device for depositing treating fluids in well tubing: acontainer having a chamber, at least one passage- Way extendingoutwardly from the chamber and at least one port longitudinaly spacedfrom the passageway; a normally extended collapsible tubular membersealingly mounted on said container with its inside in pressurecommunication with said chamber through the passageway, said tubularmember being initially collapsed by the well pressure; a longitudinallymovable member transversely mounted within the chamber and sealing withthe interior of the chamber adapted for the application of a forceagainst the side thereof facing the passageway to locate said member ata point in the chamber between said passageway and said port; and asupport member mounted on the container and extending into said chamberand adapted to position said longitudinally movable member so that thepressure in the well tubing is applied through the port and against theother side of the longitudinally movable member so that as the device islowered down the well and a force is applied against the longitudinallymovable member greater than the force against the side of thelongitudinally movable member facing the passageway, the longitudinallymovable member is moved to a point in the chamber to permit the pressurein the well tubing to be applied through the passageway to extend thetubular member against the inside of the tubing.

6. A device in accordance with claim 5 wherein said tubular member is arubber tubular member and has bow springs therein for normally biasingthe tubular member to an extended position.

7. A device for depositing a chemical in a Well comprising: a containerprovided with a chamber defined by the inside of the container andhaving one elongated portion of larger cross-section than anotherelongated portion, and an outlet orifice in fluid communication with thesmaller cross-sectional portion and at least one port in iluidcommunication with the larger cross-sectional portion; a differentialpiston arrangement including one por tion of smaller cross-sectionalarea than another portion, the smaller cross-sectional end being movablewithin the smaller cross-sectional portion of the chamber and the largercross-sectional portion being movable Within the larger cross-sectionalportion of the chamber, said larger cross-sectional portion beingsubjected to the well pressure applied through said port; a chemicalcontained within the smaller cross-sectional portion of the chamber andin contact with the smaller cross-sectional end of the diierentialpiston arrangement; means for normally preventing movement of the pistonarrangement, said means being responsive to a predetermined wellpressure applied through the port to permit the movement of the pistonarrangement to ow the chemical from the smaller crosssectional portionof the chamber and out through the orice.

8. A device for depositing a corrosion inhibiting chemical in the insideof well tubing comprising: a normally vertical elongated tubularcontainer provided with an elongated cham-ber dened by the inside of thetubular container and having one elongated portion of larger crosssection than another elongated portion, and an outlet oriiice in fluidcommunication with the smaller crosssectional portion; a chemicalcontained within the smaller crosssectional portion; means normallypreventing me ejection of the chemical through the orice and responsiveto a predetermined well pressure to permit the ejection of the chemicalthrough the oriice; a smaller piston having a cross-sectional areasubstantially the same as the smaller cross-sectional portion of thechamber and a larger piston having a cross-sectional area substantiallythe same as the larger cross-sectional portion of the chamber; a pistonshaft interconnecting said pistons and having a length suiiciently longto restrain movement of the smaller piston to Within the smallercross-sectional portion regardless of the position of the larger piston;said pistons being disposed within the chamber so that the chemical inthe smaller cross section of 4the chamber normally rests against the4free end of the smaller piston; a naturally extended collapsible means;means for connecting said collapsible means to said tubular container soas to hold said collapsible means over pressure-equalizing ports formedin the container to interconnect the larger cross-sectional portion ofthe chamber and the inside of the collapsible means, saidpressure-equalizing ports being positioned longitudinally with respectto the larger cross-sectional portion of the chamber to permit the freeend of the larger piston to be moved past the ports; and meanspermitting the well pressure to be exerted against the free end of thelarger piston causing at Ia predetermined well pressure the overcomingof the means normally preventing the ejection of the chemical throughthe orice so that the chemical is ejected and the free end of the largerpiston moved beyond the equalizing ports causing the Well pressure to beexerted against the inside ofthe collapsible means to equalize thepressure on the inside and outside of the collapsible means tot allowsaid collapsible member to extend against the tubing whereby thenaturally extended collapsible member performs a wiping and distributingaction on the chemicals as the device is owed to the surface.

References Cited in the file of this patent UNITED STATES PATENTS1,725,979 Ennis Aug. 27, 1929 2,103,475 Lindsly Dec. 28, 1937 2,526,021Fultz Oct. 17, 1950 2,636,565 Williams Apr. 28, 1953 2,698,057 KellyDec. 28, 1954 2,740,478 Greene Apr. 3, 1956 2,740,481 Arterbury et alApr. 3, 1956

